Art of producing lubricants



Patented June 17, 1941 2,246,312 ART or PRODUCING LUBRICANTS EugeneLieber, Linden, N. J.,

ard Oil Development Company,

Delaware assignor to Standa corporation of No'Drawing. ApplicationOctober 29, 1938, Serial No. 237,742

7 Claims. ((1252-57) The present invention relates to the art ofproducing lubricants, and more specifically to lubrieating oils of lowpour point, by the addition of pour depressants or wax modifyingv agentsto waxy oils, and also to processes for producing such depressants ormodifiers.

Wax modifying agents are made by condensation or polymerization ofvarious materials, but exhaustive-studies have shown that a great manypolymers or condensation agents do not have these valuable properties.Most modifying agents are prepared from waxy hydrocarbons or materialswhich have a wax-like structure attributable to a relatively longhydrocarbon chain. It has now been discovered that valuable depressantsor modifiers can be prepared from cheaper sources of materials andspecifically from naphthenic acids which occur naturally in certaincrude oils, notably those obtained from the Gulf Coast of the U. S.,certain portions of California, Roumania, Venezuela and elsewhere.

This new type of depressants, as stated above, is produced fromnaphthenic acids. Such acids are separated from the crude oil orfractions wherein they occur by known methods and they may be purifiedto .whatever degree appears to be desirable. Such processes, being nopart of the present invention, need not be described in detail. In thepresent process, the naphthenic acids are first converted into acidhalides, preferably chlorides, by treatment with phosphorus chloride orthe equivalent halides of the metalloids, for example, thionyl chloride.The reaction progresses smoothly at the temperature of boiling water andthe acid halide forms a layer which may be readily decanted.

The naphthenyl halides are then polymerized or condensed to produce thewax modifiers. The reaction may be'effected by thermal means alone attemperatures from about 400 to 750 F., care being taken to avoidcarbonization by too high or too rapid heating or by heating which isnot uniform. It is desirable to thoroughly stir the polymerizationproduct during reaction, preferably by passlng a current of nitrogen orother inert gas through the reaction mixture so as not only to causeagitation, but likewise to remove hydrogen chloride vapors which areevolved dur ing the reaction. The heating is continued for several hoursuntil the evolution of hydrogen chloride has practically ceased. Theproduct thickens during the heating and it is desirable to conduct thereaction under a reflux condenser so as to permit the escape of the acidvapors and to return liquid materials for further reaction.Pblymerization may be continued for some time after the acid evolutionhas practically ceased, but too long a heating is undesirable as solidsare apt to be formed.

If desired, polymerization may be effected by the aid of catalysts,particularly aluminum chloride or its equivalents among the group ofFriedel Craft or active halide catalysts. The conditions of reaction aresubstantially the same as given above; a temperature of at least about400 is required, but it is preferable not to conduct the heating aboveabout 500 F., in the presence of these active catalysts. The time ofreaction is about the same as given above and the results aresubstantially the same.

After polymerization has been effected, the product is preferablydiluted with kerosene or a similar solvent and the solution is washedwith aqueous alcohol to remove the remainder of the acid. If catalyst.is used, its hydrolysis is accomplished by the addition of the aqueousalcohol and the catalytic sludge separates from the solid layer so thatit is readily removed in this way.

The kerosene or other solution is then distilled, preferably with fireor 600 F., in order to remove the kerosene and the lower boilingfractions of the polymer.

The product recovered as a distillation residue is thick, viscous andgummy, usually of a dark green to brownish color, and is freely solublein mineral oils. It may be further purified by sulfuric acid treatment,but if it has been carefully prepared, it is suitable for use as such.

As a pour point depressant, the material is add ed to the oil inproportion from about .1 to 5%. It will be understood that like otherdepressants, the potency of the material depends to some extent on theparticular samples of naphthenic acids available, and likewise thedifferent oils show dif-. ferent susceptibility to the action of thesedepressants. As wax modifying agents, the materials are used insubstantially the same amounts and are added to the waxy oil eitherbefore or after it is diluted with the wax separating solvents. Theactual separation of wax is made by sedimentation, centrifugation orfiltration, and it is greatly assisted by the presence of thesemodifying agents.

Example I Eighty-eight grams of refined naphthenic acids from Colombiancrude oil were converted'to the naphthenyl chloride by heating with .onemolecular proportion of thionyl chloride.- When evolu tion of sulfurdioxide and hydrogen chloride had ceased, thenaphthenyl chloride wastransferred to a suitable reactor fitted with a thermometer and outlettube for HCl gas.

mixture slowly heated to 450 F. and maintained thereat for 5 hours, atwhich time the evolution fire and steam to 600 F. to remove low boilingand steam, up to about 500 10 grams of anhydrous AlCla were added all atonce and the viscous oil was obtained. This is a yield of 61 percentbased on the naphthenic acids. The pour depressor potency was tested byblending in a waxy-oil. The following results were obtained:

Pour point F. Original oil; +30 Original oil +1 polymerized col. napht.acids Original oil |-5% polymerized col. napht.'acids 20 (betterthan)Example 11 The procedure and quantities of Example No. I were repeatedexactly except that the poly- 'merization was carried out in the absenceof catalyst. Example No. II comprises two individual cases. In thefirst, the reaction was carried out at 400 F. for 5 hours, whilein thesecond the reaction temperature was maintained at 480 F. for 5 hours.The recovery of the products wa the same as described previously. Thefollowing table gives the results obtained:

A. s. 'r. M. potency Percent Reaction tom "F.

' ymld Percent Pour point,

added F.

4 0 52 5 5 490 60 5 5 Blank +30 Example III 125 grams of naphthenicacids obtained from Venezuelan crude oil were converted to thenaphthenyl chloride asdescribed in Example No. I. The resultingnaphthenyl chloride was placed in a suitable reactor fitted with areturn condenser, thermometer and inlet tube for inert gas (nitrogen).15 grams of anhydrous AlCla were added as quickly as possible. A rapidstream of inert gas was passed through the mixture and the temperatureraised to 450 F. and maintained thereat for 5 hours, at which time theevolution of 1101 had practically ceased. After cooling the product wasrecovered as described in Example No. 1. Ayi'eld of 67% based on thenaphthenic acids was'obtained. The pour depressor potency was obtainedby blending in a waxy-oil. The following result was obtained:

Pour point F. Original oil +30 Original oil+5% polymerized I naph.acids. (betterthan) 2,246,812 material. A residue of 54 grams of a darkgreen a Exam IV The procedure and quantities of naphthenic acids andA101: of Example No. III were repeated exactly except that the mixturewas not agitated with nitrogen gas. The recovery of product was the sameas before. A yield of only 32% based on the naphthenic acids wasobtained. When blended to the same concentration (5%) as in Example III,the pour point of the waxy-oil was -10 F.

The polymerization-condensation products per se and the method 01'preparing same are claimed in copending' application Serial No. 371,994,filed December 27, 1940.

The present invention is not to be limited by any theory of themechanism of the reaction the presence of aluminum chloride at a tem---perature from about 400 F. to 500 F.', hydrolyzthe presence 3. Acomposition of matter comprising a waxy lubricating oil and a smallquantity of a condensation product prepared by heating naphthenic acidhalides within the temperature range of 400 F. to 750 F.

4. A composition of matter comprising a waxy lubricating oil and a smallquantity of a condensation product of a naphthenic acid halide preparedby heating naphthenic acid halides in of acataiyst of the Friedel andCrafts type.

5. A composition of matter comprising a waxy lubricating oil and acondensation product ob-' tained by heating a naphthenic acid chloridein ing the catalyst and removing the products'oi' the catalysthydrolysis and distilling oi! the low boiling products.

6. Composition according to claim 3 in which the condensation product isprepared by heating the naphthenic acid halide in the polymerizationcatalyst.

7. Composition according tdclaim 3 in which: the condensation product isprepared by passing an inert gas through the reaction-mixture to -causeagitation and to remove evolved hydrogen halide vapors during thecondensation. v EUGENELIEB'ER.

absence of a

